Once you've ramped up, your reward 'matches' your hash rate when the block is found, since that is (expected to be) your hash rate for the last 5Nd also.
The variance the 5Nd deals with is during changing hash rates.
If you have the same hash rate (forever) then the 5Nd makes no difference to you after you've ramped up, until you ramp down.
Kano's post above is why the 5nd ramp up is a non-issue for me. 5nd reduces pool variance. For miners this is helpful to not miss rewards if you need to do miner maintenance or have power/internet outages.